Valve seat grinding apparatus



Aug. 18, 1953 P. WEYNAND VALVE SEAT GRINDING APPARATUS s Shegs-Sheet 1Filed Dec. 29, 1952 FIG. l2

FIG. I

R .w N 1 E 1, w w M m Patented Aug. 18, 1953 UNITED STATES PATENT OFFICEVALVE SEAT GRINDING APPARATUS Paul Weynand, San Antonio, Tex.

Application December 29, 1952, Serial No. 328,294

12 Claims. l

My invention to valve seat grinding apparatus, and more particularly toapparatus most suitable for acting upon the intake and exhaust valveseats of internal combustion engines, especially aircraft engines,although not necessarily limited to such.

The principal object of the invention is to provide apparatus which maybe quickly and accurately assembled with respect to parts of the enginefor operating the grinding element, preferably by an electric motor, andfeeding the grinding element toward and against the valve seat withminute accuracy, so as to not grind more of the metal of the seat thanis necessary to condition it for proper relationship with respect to thevalve.

Another object is to provide apparatus embodying a drive shaft, adaptedto extend through the opening of the valve seat, to which motion isimparted by the motor, and a unit, which carries the grinding element,which may be quickly attached to and in driven relationship to the driveshaft and quickly detached therefrom for the purpose of inspecting thevalve seating surface of the seat, from time to time, and so as todiscontinue further grinding when the seat has been properly surfaced.

A further object is to provide apparatus in which the driving shaft, foroperating the grinding element or stone, extends through and beyond theusual pilot, into the zone in which the cam follower, following springetc. usually operates, and impart rotation to such extending portion ofthe driving shaft, instead of to the end thereof which is adjacent tothe valve seat.

Other objects and advantages of the present invention will appear in thefollowing detailed description of the preferred embodiment thereof,taken in connection with the accompanying drawings, forming a part ofthis specification, and in which drawings:

Fig. 1 is a view of the apparatus in elevation, and showing a portion ofa conventional engine, at the zone of the valve seat, guide etc., inver-.- tical section.

Fig. 2 is an enlarged vertical sectional View of the apparatus throughthose portions thereof, coupled to the valve guide, grinding element andmeans for detachably connecting the grinding element to the drive shafttherefor, the shaft being shown in elevation.

Fig. 3 is an enlarged plan view looking in the direction of the arrowsof line 3--3 of Fig. 2.

Fig. 4 is an enlarged sectional view on the line 4-4 of Fig. 3.

3? as shown in Figs. 1 and 10 which in turn may Fig. 5 is a sectionalview on the line 5-5 of Fig.2.

Fig. '6 is a view partly in elevation and partly in vertical section ofthe pilot, a portion of the drive shaft extending therethrough beingshown in elevation.

Fig. '7 is a sectional view on the line 1-4 of Fig. 6.

Fig. 8 is a View partly in vertical section and partly in elevation ofmeans for attaching the apparatus to the valve guide.

Fig. 9 is a sectional view on the line 99 of Fig. 8.

Fig. 10 is a view in elevation of the drive motor, and partly inelevation and partly in vertical section of means for feeding thegrinding element toward and from the work.

Figs. 11 and 12 are sectional views on the lines ilii and i2-I2,respectively, of Fig. 10.

In the drawings I disclose parts of an aircraft engine comprising aportion M of the engine body, a circular valve seat I5 and a cylindricalvalve guide it carried by the body portion 14, all of which may be ofconventional and well known design. In the example shown the body Mprovides a valve well IT, a constricted portion is supporting the guide[6 and a skirt portion is which surrounds a portion of the usual valvespring etc., not shown in the drawings. The end portion 251 of the guideextends into the chamber 2| formed by the skirt portion I9.

Broadly the apparatus, according tothe present invention comprisesengine carried mechanism 23 and mechanism 24 separate from the engineand which may be supported on a panel form a part of a servicing standor bench, not shown in the drawings.

The mechanism 23 comprises a tubular pilot 2% coaxial with andnonrotatably carried by the guide it, and having afirst or lower endportion in the zone of the guide and a second or upper end portionlocated beyond the valve seat l5; a means 21 for detachably connectingthe pilot 25 to and coaxial with the guide I 6; a drive spindle 28extending through the pilot with its upper end portion extendingupwardly beyond the valve seat l5 and its lower portion downwardlybeyond the lower end of the pilot; a means 29 carried by the guide Itretaining the spindle c0- axial with the pilot and guide in a mannerthat the spindle may be rotated and moved axially;.

a circular grinding element 38 for acting upon the valve seat l5; andmeans 31 detachably securing the element 3% to the upper end portion ofthe spindle 28, coaxial therewith and for rotation and axial movementwith the spindle.

The mechanism 24, in the example shown comprises an electric motor 32including a drive shaft 33; means 34 slidably mounting the motor on thepanel 25 for movement in a path longitudinally of the shaft 33; means 35detachably coupling the shaft 33 to the lower end portion of spindle 28,and manually operable means 35 for moving the motor in the path abovereferred to and hence the shaft 33 in an axial direction whereby thegrinding element, through the coupling means 35, spindle 28, and means3| may be brought into contact with and separated from the valve seatl5.

Referring now to the pilot 26, its upper end portion may be tapered asat 38 to facilitate guiding a portion of means 3i upon the pilot; itsintermediate portion may be provided with a tapered circumferentialenlargement 35 which, in eifect, forms a part of means 2! since it isfor partial engagement in the upper end portion of guide It, like astopper; and its lower portion may be split longitudinally for a shortdistance providing the slits 48 shown in Figs. 6 and '7, and providedwith a tapered, screw threaded bore ll for receiving a tapered, screwthreaded collet 52, which when turned tight expands the split endportion of the pilot into intimate contact with the bore of pilot 25.This collet together with the enlargement 35 comprises suitable means 27for detachably connecting the pilot to and coaxial with the guide H5.

The drive spindle 28 is preferably made with its intermediate portion ofa diameter appreciably less than the internal diameter of the bore ofpilot 25 to avoid contact therewith. For purposes to be subsequently setforth the spindle has its lower end portion, below the lower end ofpilot, of reduced diameter, providing a downwardly facing shoulder 55,and its lower terminal end screw threaded as at 45; and its upper endportion reduced to provide a polygonal or non-circular formation as at41, and an upwardly facing shoulder 43, and terminating in afrusto-pyramidal or conical end 49 to facilitate disposing the means 59in operative relation to the spindle. The upper end portion may also beprovided with a circumferential groove 50 in a plane above the shoulderit for cooperation with a preferred part of means 38.

With reference to the means 29, at the lower portion of the enginecarried mechanism 23, it may comprise a cylindrical bearing supporthousing 52, the upper end portion of which is provided with a tapered,screw threaded bore 53 and its lower end portion closed by a detachablecap 54 through a central opening 55 of which extends a portion of thelower end of spindle 28 and a surrounding retainer sleeve 55 engaging aninner race of a lower anti-friction ball bearing 57 disposed in thechamber 58 of the housing 52. The upper portion of the housing is closedby a tapered collet 69 received in bore 53, the collet being splitlongitudinally to provide slits 6| shown in Figs. 8 and 9. The internaldiameter of the collet is normally such as to permit its being slippedon the lower end portion 25 of the guide i6, but when screwed home,tightly embraces the guide and secures the housing 52 to the guide. Thehousing may be provided, near its upper end with a lateral port illthrough which lubricant may be introduced in the chamber 58, the portbeing closed by a plug 52. The housing 52 is also provided withparallel, longitudinal slots 53 in the wall of chamber 58 open to thebottom of the chamber for the reception of lugs 55 on a bearing carrier65 which supports the outer race of lower bearing 58 as well as theouter race of an upper anti-friction ball bearing 55, the lugs in theslots preventing rotation of the outer races but permitting bodilymovement of the bearings longitudinally in the chamber 58. The innerrace of bearing 56 abuts against shoulder M. An inner spacer ring 51 andan outer spacer ring 58 are disposed between the inner and outer races,respectively, of the bearings 5'! and 65. The inner races and ring 6'!are clamped tight to the spindle between the shoulder 54 and the upperend of retainer sleeve 55 by a nut 59 on the screw threaded end 55 ofthe spindle which engages the lower end of the retainer sleeve. Theouter races and the ring 55 are clamped tight upon a lower flange ll ofcarrier 55, by a screw threaded retainer ring 12. A suitable oil sealring it may be provided in cap 55 surrounding the retainer sleeve 55.

Circular grinding elements 35 are currently available provided with aninternally screw threaded bushing i5 and the means 5i, in the exampleshown, is for association with such bushing. Such means includes aperipherally screw threaded driving disk '56 connected with the spindle28 for rotation and axial movement therewith, as by the provision of anoncircular hole Tl therein to slidably fit onto the noncircularformation 4'? of and rest on the shoulder l i of spindle 28, with alatch mechanism 78 cooperating with the groove 55 to hold it firmly inplace. For cornpactness the underface of disk 55 has a concentriccircular recess 19 to receive the upper end of an externally screwthreaded retaining collar 35 associated with the upper end portion of aninternally screw threaded inner bearing race sleeve ill which telescopeson the upper end portion of pilot 2B. The upper face of the disk is alsopreferably provided with a concentric circular recess 82 in which isdisposed a circular resilient member 5i surmounted by a metallic ring 53preierably-rounded at its upper peripheral portion as shown in Fig. 4.The disk it is in screw threaded engagement with a depending combinedbearing housing and carrier 55 for the grinding element 35. The lowerend of the housing portion has an inwardly extending flange 35 and adepending externally threaded nipple 85 upon which the bushing 75 isscrewed to bear against the flange 85. Within the chamber of housing 8-4is an upper anti-friction roller thrust bearing 8'? the outer race ofwhich engages disk 75 and the inner race, the sleeve 8! and the head ofcollar 80. Also within the chamber of the housing is a loweranti-friction roller thrust bearing 53 the outer race of which engagesflange 85 and the inner race, the sleeve 8|, there being a spacer sleeve85 between the outer races of bearings 88 and 58. The disk 16 is used topress the outer races and sleeve 89 tight against flange 85 and so thatthey rotate with the housing 85. The inner races of the thrust bearingsare held in proper bearing relation with the rollers thereof by anexpansion spring 99 as shown in Fig. 2. The inner bearing race sleeve 8|is provided with a lug 5! extending in a longitudinal groove 92 open tothe upper end and the side of pilot 25 to restrain the, sleeve 8! fromrotation, and permit the grinding element carrier means to be removedfrom association with the pilot and spindle 28.

The latch mechanism i8 comprises a segmental latch plate 93 having asymmetrical disposed notch 94 to receive the neck of the spindle 28 atthe groove 50, the plate 93 being pivoted, as by screw 95, so that itmay be swung to an unlatched position. The plate 93 bears upon the ring83 when in a latched position and preferably causes slight compressionof the ring 5I. To assist in holding the plate 93 in a latched positionit is provided with a notch 95 offset from notch 94 to receive the shankof a headed screw 91. To facilitate latching and unlatching the plate isprovided with an upstanding finger piece or lug IllI remote from thepivot screw 95. There may also be provided a spring urged ball 98carried by plate 93 adapted to engage in a recess 99 open to theunderside of the plate when it is inv a latched position and to engagein a similar recess I09 when unlatched.

Referring now to the mechanism 24 more in detail, and as shown in Figs.1, l and 12, the motor 32 may be electrically operated and of standardmake, since it is not necessary to make it small enough to enter thecylinder of a radial type aircraft engine of the general character shownin Patent No. 2,363,384 granted November 21, 194 1, the motor of thepresent apparatus being exteriorly of the engine cylinder. The means 34slidably mounting the motor 32 may include a base plate I82 providedwith parallel Webs I03 extending from one face thereof, and inwardlyprojecting flanges I04 on the webs parallel to each other and to theplane of base I02. The confronting edges of the flanges are beveled asat IE5 for slidable engagement with the beveled faces IE6 of rails Illlsecured to the panel as by screws I09 and Hill. The latter screws may berelatively long and have expansion springs III) encircling their shanksand bearing against the screw heads and the respective rail they supportto guard against lateral play between the rails and their respectiveflanges and which might otherwise result in vibration when the apparatusis in use. The motor 32 is secured to base plate 92 by screw III.

Means in the example shown more particularly in Figs. 1, l0 and 11,includes a connecting member H2 secured to an end of the shaft of themotor as by cross pin lit, the member IE2 being provided with anexternally screw threaded projection I54; and a socket carrying cup H5provided with a lower end screw threaded socket IE6 receiving theprojection with a relatively large washer II? interposed between thetwo. The hollow of cup I i5 is stepped so as to have a relatively deepbut narrow lower, closed-bottom chamber IE8 and a larger upper chamberII!) which is octagonal in cross-section as shown in Fig. 11. In theexample shown, the nut 69 functions also as a part of means 35 andtherefore is also of somewhat modified spherical shape in that it isoctagonal in horizontal cross section to fit, with sliding contact, thewalls of chamber H9 and act as a universal joint therewith. The chamberH9 has therein a socket member I20 the head I2I of which engages thebottom of nut 69 and the depending stem I23 of which extends partiallyinto the chamber IIB. An expansion spring I22 surrounds the stem andurges the socket member ml into intimate contact with the lower portionof nut 69. In order to detachably couple the nut to the cup I I5 so thata downward pull upon same will be transmitted to the spindle 28, Iprovide a plurality of radial holes I24 in the wall of chamber II9adjacent the upper portion thereof, having constricted openings to thechamber H9 in which are balls I25 of a diameter slightlyv greater thanthe thickness of the chamber wall. These balls are adapted to be forcedpartially through the constricted openings of holes IN to engage the nut69 above its girth, as shown in Fig. 10, by a sleeve I26: telescopicallyarranged about the socket carrying cup I I5 and normally spring biasedto a position where the balls I26 engage the inner face of the sleevewhen the balls are in coupling relation to the nut. However, the,sleeveI25 is provided with a circumferential groove I21 open to its interiorand normally above the holes I24. It is into this groove I21 that theballs may move when the sleeve I26 is lowered against action ofexpansion spring i313 interposed between a shoulder I3I of sleeve I26and the washer I ll, so as to detach the nut 69 and socket carrying cupone from the other.

The means 36 in the example shown comprises a nut I32 rigid with themotor 32, the axis of the nut being parallel with the path of movementof the motor; a screw I33 in threaded engagement with the nut, andhaving a shank i34 rotatably. carried by and extending into a housingI35 mounted on the panel 25; a member I3t which is provided with asocket portion I375 adapted to be manually rotated, as by any suitablewrench, not shown in the drawing, and a shank I38 rotatably carried byand extending into the housing I35; and speed reducing gearing I 56Within the housing !35 operatively connected to the shanks I38 and I84for imparting rotation of the former to the latter. The gearing Mil maycomprise a pinion IdI, rigid on shank I38, and a gear I42 in meshingrelation therewith, the gear being rigid on shank I3 3. The end of shankI35 opposite the screw I33 may be received in an adjustable step bearingI433 carried by a removable bottom M l forming a part of the housingI35. The step bearing is externally threaded for reception in a screwthreaded opening M5 in bottom Hit, and a lock nut M5 is provided toretain the step bearing in an adjusted position.

Ihe operation of the apparatus may well be understood from the foregoingdetailed description of a typical embodiment of my invention. However,it is desired to point out that important features of the invention arethe ability of the workman to accurately attach the engine carriedmechanism 23 in place against vibration; the motor 32 being outside thecylinder of the engine, in the case of a radial type aircraft engine, arelatively large, inexpensive motor may be used without the necessity ofusing a flexible shaft; the grinding operation may be carried out withprecision, since the means 36 provides very minute feeding of thegrinding element 30 against the work upon one turn of the manuallyoperable member I 36 due to speed reducing gearing Hi0 and the screw 533actuating the nut I32; the resilient member 5! may yield in the eventthat means 36 is operated so rapidly as to be likely to overload themotor or excessively heat the grinding wheel and valve seat, if therewas a positive feeding of the grinding wheel upon the work; and theworkman may inspect the progress being made during the grindingoperation at frequent intervals by unlatching and removing the means 3!from the drive spindle without disturbing the rest of the mechanism.

I claim:

1. In grinding apparatus for use with a circular valve seat and valvestem guide, carried by an engine body portion, the combination of enginecarried mechanism comprising, a pilot coaxial with and nonrotatablycarried by said guide, a spindle extending through said pilot having afirst end portion extending beyond the guide at its end remote from theseat and a second end portion extending beyond the seat, a first meanscarried by the engine body portion supporting said spindle for rotationand longitudinal movement coaxial with said pilot, a circular valvegrinding element, and a second means coupling said grinding element toand for rotation with said second end portion of the spindle; and secondmechanism separate from the engine for rotating and impartinglongitudinal movement to said spindle, comprising, a rotatable andaxially movable drive shaft, a third means coupling said shaft with saidspindle, and manually operable means for moving said drive shaftlongitudinally whereby said grinding element may be brought into contactwith and separated from the valve seat.

2. The combination of claim 1 in which said second means includes latchmechanism associated with the spindle whereby the second means andgrinding element may be removed from the spindle for inspection of thevalve seat while the remainder of said engine carried mechanism remainsin place.

3. The combination of claim 1 in which said drive shaft is a part of amotor mounted for movement in a path longitudinally of the shaft andsaid manually operable means is operatively connected to the motor forbodily moving it in said path.

4. The combination of claim 3 in which said manually operable meanscomprises an element to which rotation may be manually imparted, arotatable screw, a nut therefor rigid with said motor, and speedreducing gearing between said last named element and screw for impartingmovement of the former to the latter.

5. The combination of claim 1 in which said third means includes auniversal joint between the drive shaft and spindle.

6. In grinding apparatus for use with a circular valve seat and valvestem guide coaxial therewith, the combination of a tubular pilot coaxialwith said guide, extending through the opening of said valve seat andhaving a first end portion in the zone of said guide and a secondopposite end portion beyond said seat, a first means detachablyconnecting said first end portion to said guide, a drive spindleextending through said pilot and beyond the second end portion thereofand reciprocable axially of said pilot, a circular valve seat grindingelement, and a second means detachably connecting said grinding elementto said spindle at its portion beyond said second end portion of thepilot for rotation with the drive spindle.

7. The combination as specified in claim 6, in which the first endportion of the pilot is split longitudinally and is provided with atapered, screw threaded bore, and said first means includes a screwthreaded tapered collet in screw threaded engagement in said bore andexpands the pilot into intimate contact with the interior of said guide.

8. The combination as specified in claim 7, in which said first meansincludes a tapered circumferential enlargement engaging in the endportion of the guide nearest said seat.

9. The combination as specified in claim 6, in which said second meanscomprises a driving disk detachably connected to and revoluble with saidspindle, a combined outer bearing housing revoluble with said disk andcarrying said grinding element, a non-rotative inner bearing sleevecarried by and coaxial with said pilot, and antifriction bearingsincluding outer and inner races engaging said housing and sleeve,respectively.

10. The combination as specified in claim 9, in which said antifrictionbearings are of the thrust type arranged in opposed relationship and anexpansion coil spring acts upon the inner races to keep the bearingstrue.

11. In grinding apparatus for use with a circular valve seat and valvestem guide coaxial therewith, the combination of a tubular pilot coaxialwith said guide, extending through the opening of said valve seat andhaving a first end portion in the zone of said guide and a secondopposite end portion beyond said seat, a first means detachablyconnecting said first end portion to said guide, a drive spindleextending through said pilot and beyond the second end portion thereofand reciprocable axially of said pilot, a circular valve seat grindingelement, a second means detachably connecting said grinding element tosaid spindle, at its portion beyond said second end portion of the pilotfor rotation with the drive spindle, and a third means retaining thespindle coaxial with the pilot.

12. The combination as specified in claim 11, in which said third meanscomprises a bearing housing, through which said spindle extends,detachably connected to said guide adjacent to the first end portion ofthe pilot, and an antifriction bearing in said housing, including anouter race non-rotatably carried by said housing and slidablelongitudinally thereof, and an inner race rotatable with the spindle andmovable axially therewith.

PAUL WEYNAND.

No references cited.

